Another difference between the 12 volt pair and a six volt series pair
The 6 volt most common in RV service is a GC-2 Golf Car DEEP CYCLE battery
You can safely run it down to half full (50% state of charge) before fast aging sets in.
Though you can get DEEP CYCLE 12 volt if you search hard enough most 12 volt batteries are MARINE/deep cycle these are really starting batteries and shoudl be kept 75-80% full or more. RUn 'em down to 60% and they start "Fast aging"
What is Fast Aging? I see folks replacing batteries 5,4,3 or even newer due to having run them down too far too often.. Mine want 9 7-10 is normal and I've heard of 12.
